Cerebral Perfusion Monitoring With Transpharyngeal Ultrasonography (TP-Echo)

Monitoring the Brain in On-pump Cardiovascular Surgery: The Role of Transpharyngeal Ultrasonography as a Non-invasive Adjunct to Assess Cerebral Perfusion

This prospective observational pilot study investigates transpharyngeal ultrasonography (TPU) as an additional neuromonitoring strategy to assess cerebral perfusion during on-pump cardiovascular surgery.

In the first part of the study the investigators will investigate the feasibility of TPU for visualization of aortic arch branches including the innominate and the carotid arteries in twenty patients undergoing coronary artery bypass grafting with extracorporeal circulation (cohort 1.). In the second part the investigators plan to adopt the investigators previous experiences on TPU to a selected population of twelve patients undergoing ascending aortic and/or arch repair in deep hypothermic circulatory arrest (DHCA, cohort 2.). In contrast to cohort 1., patients in cohort 2. are exposed intraoperatively to intermittent cerebral perfusion stops or reductions due to surgical procedure, perfusion technique and their underlying disease (aortic dissection or aortic aneurysm).

The investigators hypothesize that cerebral perfusion monitoring using TPU as a non-invasive technique provides a simple and real-time adjunct to assess blood flow velocity in the extracranial cephalic vessels with Doppler ultrasound. Especially in aortic arch surgery with its inherent risk of cerebral hypoperfusion TPU might be a valuable adjunct to routine.

Study Overview

• Status: Terminated
• Conditions: Cardiopulmonary Bypass
• Intervention / Treatment: Device: Transpharyngeal ultrasonography; Device: Duplex sonography

Detailed Description

Background

Cerebral hypo- or malperfusion during cardiovascular surgery can lead to grave consequences including transient cerebral ischemia or stroke impairing patient's daily life and affect surgical outcome. For this reason a multimodal neuromonitoring strategy using a variety of devices (evoked potentials, near-infrared spectroscopy, transcranial Doppler ultrasonography) with different technologies has been recommended by medical societies. These techniques have various limitations and cannot be used in all clinical situations. In contrast, transpharyngeal ultrasonography (TPU) represents a simple and readily available technique: the transesophageal echocardiography probe, routinely placed in most cardiac surgical patients for monitoring and assessment of surgical results, will be withdrawn into the upper esophagus making the visualization of supraaortic branches possible.

To date, there are several reports about imaging of aortic arch branches using TPU. The utility of this technique, however, for systematic cerebrovascular monitoring has not have been investigated so far.

Objective

The aim of this study is to investigate TPU as a cerebrovascular monitoring adjunct in two cohorts of on-pump cardiac surgery procedures. Clinical feasibility and diagnostic accuracy of antegrade carotid flow detection are compared to the established reference methods of Duplex sonography and transcranial Doppler ultrasound.

Methods

All patients receive anesthetic and surgical management according to institutional standards. Patient enrollment in the study occurs consecutively and unblinded for surgical procedure.

All patients receive TPU, Duplex sonography and transcranial Doppler examination after anesthesia induction preoperatively, during extracorporeal circulation and after weaning from cardiopulmonary bypass. In addition, the patients in cohort 2.(ascending aortic repair with DHCA) receive above mentioned noninvasive ultrasound / Doppler measurements also during the period of DHCA with and without antegrade cerebral perfusion.

Image acquisition and data extraction are conducted by different persons to avoid investigator-related bias.

• Study Type: Observational
• Enrollment (Actual): 32

Contacts and Locations

Study Locations

• Switzerland
  • Bern, Switzerland, 3010
    • Dep. of Anesthesiology and Pain therapy

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Probability Sample

Study Population

Patients undergoing cardiac surgery at the University Hospital Bern.

Description

Inclusion Criteria:

• Signed informed consent
• Cardiopulmonary bypass procedure (normo-(group 1) or hypothermic (group 2))

Exclusion Criteria

• Contraindication for transesophageal echocardiography
• Carotid artery stenosis

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Cardiopulmonary bypass group; Patients requiring normothermic (or mild hypothermic) cardiopulmonary bypass.	Device: Transpharyngeal ultrasonography; Transpharyngeal Dopplerultrasonography (Device: iE33 xMatrix Philips). Assessment of cerebral blood flow by detection of blood flow velocities in the extracranial carotid arteries.; Device: Duplex sonography; Assessment of cerebral blood flow by detection of blood flow velocities in the extracranial carotid and middle cerebral arteries during coronary artery bypass grafting.
Hypothermic Cardiopulmonary Bypass Group; Patients requiring (deep) hypothermic cardiopulmonary bypass.	Device: Transpharyngeal ultrasonography; Transpharyngeal Dopplerultrasonography (Device: iE33 xMatrix Philips). Assessment of cerebral blood flow by detection of blood flow velocities in the extracranial carotid arteries.; Device: Duplex sonography; Assessment of cerebral blood flow by detection of blood flow velocities in the extracranial carotid and middle cerebral arteries during coronary artery bypass grafting.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
accuracy of cerebral flow velocity measurement	Cerebral blood flow velocity measurements will be performed using the pulsed wave Doppler technique. Doppler peak flow velocities (obtained at the same intraoperative phase and at the same time) will be compared between the different Doppler techniques.	intraoperative phase, expected to be ca. 4 hours

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
clinical feasibility	Clinical feasibility will be assessed by analyzing the accuracy of data concordance, i.e. location of cerebral blood vessel, blood flow velocity and cerebral vessel area between the different Doppler techniques. Data will be plotted using Bland-Altman analysis.	intraoperative phase, expected to be ca. 4 hours

Collaborators and Investigators

• Sponsor: University Hospital Inselspital, Berne
• Investigators: Study Chair: Balthasar Eberle, Prof., MD., University Hospital Bern, Dep. of Anesthesiology and Pain therapy

Publications and helpful links

General Publications

• Bevilacqua S, Romagnoli S, Ciappi F, Ridolfi N, Codecasa R, Rostagno C, Sorbara C. Transpharyngeal ultrasonography for cannulation of the internal jugular vein. Anesthesiology. 2005 Apr;102(4):873-4. doi: 10.1097/00000542-200504000-00038. No abstract available.
• Shimizu H, Matayoshi T, Morita M, Ueda T, Yozu R. Total arch replacement under flow monitoring during selective cerebral perfusion using a single pump. Ann Thorac Surg. 2013 Jan;95(1):29-34. doi: 10.1016/j.athoracsur.2012.08.007. Epub 2012 Oct 4.
• Orihashi K, Matsuura Y, Sueda T, Watari M, Okada K, Sugawara Y, Ishii O. Aortic arch branches are no longer a blind zone for transesophageal echocardiography: a new eye for aortic surgeons. J Thorac Cardiovasc Surg. 2000 Sep;120(3):466-72. doi: 10.1067/mtc.2000.108289.
• Nanda NC, Miller AP, Nekkanti R, Aaluri S. Transpharyngeal echocardiographic imaging of the right and left carotid arteries. Echocardiography. 2001 Nov;18(8):711-6. doi: 10.1046/j.1540-8175.2001.00711.x.
• Immer FF, Moser B, Krahenbuhl ES, Englberger L, Stalder M, Eckstein FS, Carrel T. Arterial access through the right subclavian artery in surgery of the aortic arch improves neurologic outcome and mid-term quality of life. Ann Thorac Surg. 2008 May;85(5):1614-8; discussion 1618. doi: 10.1016/j.athoracsur.2007.11.027.

Study record dates

Study Major Dates

• Study Start: April 1, 2013
• Primary Completion (Actual): March 1, 2018
• Study Completion (Actual): March 1, 2018

Study Registration Dates

• First Submitted: March 27, 2013
• First Submitted That Met QC Criteria: April 9, 2013
• First Posted (Estimate): April 10, 2013

Study Record Updates

• Last Update Posted (Actual): April 5, 2018
• Last Update Submitted That Met QC Criteria: April 3, 2018
• Last Verified: April 1, 2018

More Information

Terms related to this study

• Keywords: Echocardiography; Cardiac surgery; Cerebral perfusion; Intraoperative period
• Other Study ID Numbers: 056/10